New regulation forces ships to lower the emissions of SO2. Ships travelling in SECA areas has to either run on low sulphur fuel, or install SO2 scrubbers. To measure the SO2 emissions from a ship is not an easy task. OPSIS provides the Port Authorities with a unique measurement principle where the emissions from the ship is measured remotely. Light is passing the emissions and by analyzing the light, concentrations of SO2 can be measured.